[hibernate-users] (no subject)

[Robert Klemme]

2007/9/4, Walden Mathews <wmathews at aladdincapital.com>:
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>
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> Hello,
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>
>
> I'm using Jboss-4.0.5-GA in the ejb3 configuration.  I'm trying to implement
> the following entities and relationships, without success:
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> Entity: Security
>
> Entity: Trade
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> Entity: Allocation extends Trade
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> Security->Trade is one-to-many with Trade as the relationship owner
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> Trade->Security is many-to-one
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> Security->Allocation is one-to-one with Allocation as the relationship owner
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> Allocation->Security is one-to-one
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> The basic idea is that while a Security may have a collection of Trades
> associated with it, at most one can be an Allocation.  And if a Security has
> an associated Allocation, then that Allocation must appear in the Trades
> collection of the Security as well.
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> I've tried this approach:
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> @Entity public class Security {
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>              …
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>              @OneToMany(mappedBy="security") public Collection<Trade>
> getTrades() {…}
>
>              @OneToOne(mappedBy="security") public Allocation
> getAllocation() {…}
>
> }

I believe this is calling for trouble because you have *two*
relationships to the *same* class (in a way, because Allocation
inherits Trade) mapped by the *same* column.  IMHO you should remove
the 1:1 to Allocation and ensure by your business logic that the Trade
collection contains only one allocation.

Maybe there is also bug in Hibernate which does not detect this
situation and issue a proper error message but IMHO the root cause is
your problem with the logic as stated above.

Kind regards

robert